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Updated median MELD at transplant scores in effect; revisions made to MMaT and MPaT scores

Published on: Friday, October 14, 2022

Effective Sept. 28, 2022, the median MELD at transplant (MMaT) values for liver transplant candidates with exception scores have been updated.

The updated scores reflect a liver allocation policy change effective June 28, 2022, that now bases MMaT on data about liver transplants performed within a 150 nautical mile radius around the donor hospital where the organ is recovered.

The revised data report displays the newly derived MMaT scores by each donor hospital. It also displays the median PELD at transplant (MPaT) score. The MPaT is a national calculation, drawing upon transplants performed nationwide, and is not based on the donor hospital. Both MMaT and MPaT scores are updated twice a year.

The national MPaT score implemented Sept. 28 was 32. Following post-implementation review, the OPTN determined that the national MPaT score and some of the MMaT scores were incorrect, as the process did not include a small subset of data needed to calculate the new values. For a brief period, the incorrect scores were implemented in the Organ Procurement and Transplantation Network (OPTN) computer matching system.

On Sept. 29, the MPaT was correctly recalculated to 35, which is the same value as in previous semi-annual score updates. The MMaT scores were also corrected. These revised values were updated in the computer matching system and are in effect as of Sept. 29. Analysis shows no impact to any adult patients.

During the brief period of time the incorrect MPaT value was in place, there were two match runs where candidates at two liver transplant programs were potentially affected. The OPTN contractor has contacted these transplant programs with information about the error. The OPTN contractor is also conducting a root cause analysis and will further consult with an independent quality review agency to identify areas of process improvement. These are in addition to ongoing quality improvement initiatives across the OPTN.

Learn more about liver allocation policy.